Ulcerative colitis (UC), Pouchitis, and Crohn's Disease are examples of Inflammatory Bowel Diseases (IBD) characterized by chronic inflammation in the intestine. The clinical symptoms are diarrhea, abdominal pain, occasional rectal bleeding, weight loss, tiredness and sometimes fever. Although occurring at any age, IBD is most common in teenagers and young adults, which consequently may suffer from delayed development and stunted growth. The frequency of the disease is similar to type 1 diabetes in Europe and the USA. The clinical course of IBD varies considerably. Patients with mild to moderate symptoms may be treated without hospitalization. However, 10-15% of patients experience a severe course of the disease, which in many cases is followed by surgery.
IBD is treated medically by reducing the inflammation and thereby controlling the gastrointestinal symptoms. However, there is currently no medical cure for IBD. Coloectomy may eliminate UC but reduces life quality and increases the risk of complications. The available medical treatments include the use of 5-aminosalicylic acid (5-ASA), corticosteroids and immunomodulatory medicaments. Prolonged treatment of mild to moderate IBD symptoms is usually carried out using 5-ASA while corticosteroids and immunomodulatory medicaments are used to treat severe symptoms. Diarrhea or abdominal pain appear as side effects of 5-ASA whereas long term use of corticosteroids frequently shows serious side effects including reduction in bone mass, infection, diabetes, muscle wasting and psychiatric disturbances. Immunomodulatory medicaments suppress the immune system, which controls the IBD symptoms. However, the resulting immuno-compromised state leaves the patient susceptible to many diseases.
Irritable Bowel Syndrome (IBS) is a condition characterized by abdominal pain and/or discomfort which is associated to altered bowel habit or defecation, where symptoms are not explained by structural or biochemical abnormalities. Urgency, bloating and feeling of incomplete bowel movements are also common in IBS. Therefore, it is classified among functional gastrointestinal disorders which include diseases such as functional bloating, noncardiac chest pain, non-ulcer dyspepsia, and chronic constipation or diarrhea (Longstreth G. H. et al., 2006). Noteworthy, IBS has a substantial impact on morbidity and quality of life beyond abdominal pain and discomfort, as the associated symptoms affect both the sufferer's sense of well-being and the ability to function normally (Dean B. B. et al., 2005).
There is a tremendous activity in the field of drug development for the treatment of IBS. In this regard, various antidepressants have gained popularity although their efficacy in clinical trials has been modest and their clinical utility is limited by untoward side effects. Serotonergic agents have demonstrated efficacy on the global symptoms of IBS. However, recent concerns about safety have severely limited their use. Therefore, the development of novel therapies for IBS is of great interest.
Probiotics are defined as “living microorganisms, which upon ingestion in certain numbers, exert health benefits beyond inherent basic nutrition” (Araya M. et al., 2002; Guarner F. et al., 1998). Several lactic acid bacteria and species from the genus Bifidobacterium are probiotic, which implies that they have been shown to promote a specific health effect. Probiotic bacteria must fulfil several requirements related to lack of toxicity, viability, adhesion and beneficial effects. These probiotic features are strain-dependent, even among bacteria of the same species. Therefore, it is important to find those strains that have a better performance in all probiotic requirements. Human clinical trials using probiotics alone or in combination with antibiotics have been performed to identify strains and/or formulations for the treatment of patients with IBD or IBS, or for keeping already treated IBD patients in remission. WO 96/29083 and EP 554418 disclose two intestine colonizing Lactobacillus strains including Lactobacillus plantarum 299v (DSM 6595) and Lactobacillus casei ssp. rhamnosus 271 (DSM 6594). EP 415941 discloses methods for preparing nutrient composition comprising treatment of oat gruel with enzymes before mixing with lactobacilli. U.S. Pat. No. 7,195,906 discloses a strain of Bifidobacterium isolated from resected and washed human gastrointestinal tract for the treatment of inflammatory diseases, especially gastrointestinal inflammatory activity, such as IBD, and IBS.
In spite of a promising potential, a considerably improvement of the effect of probiotics for use in the treatment of inflammation bowel diseases (such as IBD) as well as of other gastrointestinal diseases (such as IBS) is needed.